The disclosure of Japanese Patent Application No. 2000-283792 filed on Sep. 13, 2000 and 2000-338043 filed on Nov. 6, 2000 including the specification, drawings and abstract is incorporated herein by reference in its entirety.
1. Field of the Invention
The invention relates to a warm-up control device having a heat storage device for warming up an internal-combustion engine quickly by utilizing a technique for storing heat using an heat insulating container.
2. Description of the Related Art
As an example of this kind of warm-up control device, Japanese Patent Application Laid-Open No. 10-71837 discloses a configuration in which coolant heat-insulated and stored in an heat insulating container as a heat storage device warms up an internal-combustion engine after flowing through an intake air heat exchanger, a heat exchanger with respect to lubricating oil in the internal-combustion engine, and a heat exchanger with respect to hydraulic fluid in an automatic transmission during warm-up, and the engine coolant in the heat insulating container circulates between the heat insulating container and the internal-combustion engine during warm-up.
Japanese Application Patent Laid-open No. 10-77834 discloses another configuration, in which coolant heat-insulated and stored in a heat storage device is used for heating engine intake air, engine oil, and automatic transmission fluid during warm-up after the start of the engine, and after warm-up (after the engine coolant temperature is increased to a predetermined value), the heating of the engine intake air by the coolant is stopped.
However, the Japanese Application Patent Laid-open No. 1.0-71837 does not teach how to circulate the engine coolant between the heat insulating container of the heat storage device and the engine. In addition, the warm-up of the engine may be delayed.
On the other hand, in the warm-up control device in the Japanese Patent Application Laid-Open No. 10-77834, heating of engine oil and heating of transmission fluid are always conducted simultaneously, and the ratio between the amount of coolant used for heating engine oil and the amount of coolant used for heating transmission fluid is fixed. Therefore, the effect of promoting the warm-up of engine oil and the effect of promoting the warm-up of transmission fluid are constant.
Actually, however, in an automotive engine, it is sometimes preferable that priority is given to either the warm-up of the engine or the warm-up of the transmission.
For example, if the warm-up of an engine is insufficient, the engine emission properties may deteriorate or the drivability may deteriorate. On the other hand, if the warm-up of a transmission is insufficient, the fuel efficiency may deteriorate due to the increase in friction loss. Depending on the use application of the engine, however, improvement of the emission properties and the drivability may take priority over the fuel efficiency, or the fuel efficiency may take priority during operation. In such cases, it is preferable that priority is given to the warm-up of the engine and the engine is warmed up earlier than the transmission, or priority is given to the warm-up of the transmission and the transmission is warmed up earlier than the engine.
Further, depending on the condition during stoppage of the engine, the temperature decreasing condition of the engine may be different from that of the transmission. For example, when the engine temperature is not decreased much but the transmission temperature is decreased, it is preferable that a heat storage tank supplies more coolant to the transmission than to the engine in order to give priority to the warm-up of the transmission.
However, as in the case of the warm-up control device.disclosed in the Japanese Patent Application Laid-Open No. 10-77834, if the ratio between the amount of coolant supplied to the engine and the amount of coolant supplied to the transmission is fixed, the warm-up of the engine or the transmission cannot take priority over the warm-up of the other. Therefore, it is not possible to perform the warm-up operation as required, or according to the temperature conditions of the engine and transmission.
In other words, in the warm-up control devices disclosed in these two publications, the coolant stored in the heat storage device cannot be distributed efficiently to drive devices such as an internal-combustion engine and a transmission as required.
In view of the above problems, it is hence an object of the invention to provide a warm-up control device for an internal-combustion engine capable of efficiently supplying a heating medium from a heat storage device to an internal-combustion engine and a location requiring temperature rise other than the engine.
In other words, a warm-up control device according to a first aspect of the invention comprises a heat storage device that stores a heating medium heated during operation of the internal-combustion engine, a first path that supplies the heating medium from the heat storage device to the engine, a second path that supplies the heat medium from the heat storage device to a location requiring temperature rise other than the engine main body, a circulation path that allows the heating medium to pass through the engine without passing through the heat storage device, and a controller that selects at least one of the first path, the second path, and the circulation path as a path for supplying the heating medium to at least either of the engine or the location requiring temperature rise according to the temperature rising condition of the engine.
The warm-up control device according to the first aspect of the invention may be constructed such that the heating medium stored in the heat storage device is supplied to the location requiring temperature rise other than the engine through the engine, prior to start of the internal-combustion engine or at the start of the engine, and the heating medium stored in the heat storage device is supplied to the location requiring temperature rise other than the engine, while a condition where the heating medium is circulated in the circulation path is maintained.
Alternatively, the warm-up control device according to the first aspect of the invention may be constructed such that the heating medium stored in the heat storage device is supplied to the engine main body prior to the start of the internal-combustion engine or at the start of the engine, the heating medium is circulated in the circulation.path after the start of the engine, and subsequently part of the circulating heating medium is supplied to the location requiring temperature rise other than the engine without passing through the heat storage device.
An example of the location requiring temperature rise other than the engine may be a drive device having a heat exchanger for exchanging heat between the heating medium passing through the engine main body and a hydraulic fluid.
A warm-up control device according to a second aspect of the invention comprises an internal-combustion engine,land a heat storage device that stores a heating medium heated during operation of the internal-combustion engine. In the warm-up control device, the heating medium stored in the heat storage device is supplied to an internal-combustion engine and a location requiring temperature rise other than the internal-combustion engine. It further comprises a sensor that detects the temperature of the engine and the temperature of the location requiring temperature rise other than the engine, and a setting device that setting the ratio between the amount of the heating medium supplied from the heat storage device to the internal-combustion engine and the amount of the heating medium supplied from the heat storage device to the location requiring temperature rise, according to the detected temperature of the engine and the temperature of the location requiring temperature rise.
According to the second aspect of the invention, it is possible to give priority to either the warm-up of the internal-combustion engine or the warm-up of the transmission, or to perform the warm-up operations in accordance with the respective temperature conditions.
In other words, the setting device sets the ratio between the amount of coolant supplied from the heat storage device to the internal-combustion engine and the amount of coolant supplied from the heat storage device to the transmission such that the amount of the coolant supplied from the heat storage device to the internal-combustion engine is larger than the amount of the coolant supplied to the transmission when the detected engine temperature is a predetermined temperature or lower
The warm-up control device according to the second aspect of the invention may be constructed such that the amount of the coolant supplied to the internal-combustion engine is larger than the amount of the coolant supplied to the transmission when the engine temperature is the predetermined temperature or lower. Thus, the internal-combustion engine temperature reaches the predetermined temperature in a short time, and priority is given to the warm-up of the internal-combustion engine. In other words, the warm-up operation is performed with priority given to the engine emission properties and drivability.
The warm-up control device according to the second aspect of the invention may be constructed such that that the amount of the coolant supplied to the transmission is larger than the amount of the coolant supplied to the internal-combustion engine when the engine temperature is the predetermined temperature or higher. Thus, priority is given to the warm-up of the transmission, and the warm-up operation is performed with priority given to the fuel efficiency of the engine when the temperature of the internal-combustion engine is high.
The warm-up control device according to the second aspect of the invention may be.constructed such that priority is given to the warm-up of the transmission, and after the transmission is warmed up to a certain extent, priority is given to the warm-up of the internal-combustion engine. Thus, the transmission is warmed up earlier, and the operation is performed with priority given to the fuel efficiency of the engine.
To the contrary, the warm-up control device may be constructed such that the priority is given to the warm-up of the transmission after the internal-combustion engine is warmed up to a certain extent. Thus, the internal-combustion engine is warmed up earlier, and the operation is performed with priority given to the emission properties and the drivability.